The inside of the head seems to be like an explosion consider subarachnoid hemorrhage, a sharp rise in blood pressure, cluster headache and other causes. 1. Subarachnoid hemorrhage: mainly caused by blood flowing into the subarachnoid space after the rupture of intracranial blood vessels, which often results in a sudden severe headache, which may be localized or total headache. 2. Sharp rise in blood pressure: If the blood pressure rises sharply beyond the ability of the cerebral arteries to regulate, the amount of blood in the brain is more than usual, which will easily lead to over-perfusion of the brain, causing severe headache, especially when it leads to cerebral hemorrhage, the headache is more obvious. 3. Cluster headache: the specific cause is not clear, may be related to genetic factors, trigeminal nerve abnormalities, vasodilatation, etc., often leading to frequent severe unilateral headaches, sometimes like an explosion, burning. The inside of the head like an explosion may also be caused by other reasons, it is recommended to consult a doctor in a timely manner to clarify the cause of targeted treatment.